Hi Matt,
I just got in contact with the multitouch and TUIO stuff when someone requested the feature. You should get an idea how it works by reading the posts starting here.
The flow goes something like this: WiimoteWhiteboard sends out cursor information according to the TUIO/OSC protocol (as UDP packets). The multitouch software needs to receive and process the TUIO/OSC messages. The Flash multitouch apps cannot directly receive UDP packets, hence a converter (Flosc) is required.
There are also other (not necessarily multitouch) apps that can process OSC messages.
Excerpt from the WiimoteWhiteboard Help:
Regarding Flash multitouch apps: I had some difficulties with the latest version of Flosc but I had success with the version of Flosc included here. Also make sure that you add the flash apps you want to run in the browser to the list of trustworthy locations.
Uwe